CN112762356A

CN112762356A - Sealing structure suitable for high-pressure plastic liner carbon fiber fully-wound gas cylinder and application

Info

Publication number: CN112762356A
Application number: CN202110069735.XA
Authority: CN
Inventors: 吕洪; 张存满; 周伟
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2021-05-07

Abstract

A sealing structure suitable for a carbon fiber fully-wound gas cylinder with a high-pressure plastic liner comprises an annular coaxial inner cylinder body and an annular outer cylinder body, wherein the outer cylinder body is provided with an annular base which is matched with a shoulder part of the liner to be sealed; a middle annular hollow structure is arranged between the inner cylinder body and the outer cylinder body and is used for embedding a bottle mouth of the inner container to be sealed; the inner cylinder body is provided with a sealing groove at one side contacting with the bottle mouth of the inner container to be sealed, and a sealing piece is arranged in the sealing groove to prevent gas from leaking from a gap between the inner cylinder body and the bottle mouth of the inner container to be sealed. The inner side of the base of the outer cylinder body is provided with a plurality of grooves matched with the convex rafters on the outer surface of the inner container to be sealed. The invention can greatly improve the reliability and stability of the sealing of the high-pressure gas storage cylinder, avoids gas leakage caused by fatigue failure under the working condition of use, and has the characteristic of simple and convenient assembly. The invention can be applied to vehicle-mounted high-pressure hydrogen storage bottles.

Description

Sealing structure suitable for high-pressure plastic liner carbon fiber fully-wound gas cylinder and application

Technical Field

The invention belongs to a sealing structure, and relates to a sealing structure suitable for a high-pressure gas cylinder, in particular to a sealing structure suitable for a high-pressure plastic liner carbon fiber fully-wound gas cylinder.

Background

In recent years, with the rapid promotion of the commercialization process of fuel cell vehicles, the driving range and cost factors of the vehicles are gradually emphasized, and a high-pressure vehicle-mounted hydrogen storage system, particularly a vehicle-mounted high-pressure hydrogen storage bottle, is one of the key factors influencing the performance and cost of the whole vehicle. China already realizes the mass production of 70MPa aluminum alloy liner carbon fiber fully-wound hydrogen storage cylinders (III-type cylinders), but because 70MPa III-type cylinders have low hydrogen storage weight specific density and high manufacturing cost, the mass application of the 70MPa III-type cylinders in fuel cell automobiles is hindered, and the development of a new generation of light-weight low-cost 70MPa vehicle-mounted hydrogen storage cylinders is a current research hotspot. The carbon fiber fully-wound hydrogen storage cylinder (IV-type cylinder) with the plastic inner container becomes a research hotspot in the field of the current high-pressure hydrogen storage cylinder due to high hydrogen storage weight-to-density and low manufacturing cost. The main technical difficulty of the high-pressure IV-type hydrogen storage cylinder is to solve the problem of hydrogen leakage caused by fatigue failure of the cylinder opening under the high-pressure use working condition of 70 MPa.

Patent document No. CN 102840440B discloses the following: the metal bottle mouth is combined with the injection molding piece, and the sealing ring is arranged between the injection molding piece and the plastic liner to prevent hydrogen leakage. The structure has the following disadvantages: the sealing reliability is not high, no sealing structure design exists between the metal bottle mouth and the injection molding part, the metal bottle mouth and the injection molding part are integrally molded by injection, the modulus of metal and plastic is different only by means of combination in the injection molding process, and the metal and the injection molding part are peeled off under the repeated charging and discharging working condition of the gas cylinder, so that the hidden trouble of hydrogen leakage is caused. Patent document No. CN 111120864a discloses the following: the metal bottle mouth is provided with a plurality of dovetail grooves and a plurality of reinforcing grooves, so that the bonding strength between the plastic liner and the metal bottle mouth is increased, and the problem of separation of plastic and metal is avoided. The structure has the following disadvantages: the design is complicated, the phase change of plastic and metal cannot be coordinated, and the metal bottle mouth and the plastic liner are integrally formed, so that the difficulty in manufacturing the liner is increased.

The currently disclosed patent mainly solves the problem of hydrogen leakage under the static condition of the cylinder mouth of the gas cylinder by the aspects of integral injection molding of the metal bottle mouth and plastic and enhancing the bonding strength of the metal bottle mouth and the plastic liner. However, the main reason for hydrogen leakage at the mouth of the plastic liner hydrogen storage bottle lies in fatigue failure of the gas bottle caused in the repeated filling process, which leads to the peeling of the metal mouth and the plastic liner which are combined closely originally, and meanwhile, because the elastic strain of the plastic is far greater than that of the metal, the difference of the deformation amount is large under the condition of high-pressure hydrogen, thereby leading to hydrogen leakage because the deformation amount of the original sealing ring between the two is insufficient. Moreover, the design of the bottle mouth sealing structure of the prior patent does not consider the influence of the reverse torque acting force on the sealing structure in the assembling and disassembling process of the cylinder valve when the gas cylinder is used. Therefore, a system solution is objectively needed for the problem of hydrogen leakage at the bottle mouth of the plastic liner hydrogen storage bottle, particularly at the working pressure of above 70 MPa.

Disclosure of Invention

The invention aims to provide a sealing structure suitable for a high-pressure gas cylinder, in particular to an IV-type hydrogen storage gas cylinder mouth structure design which can be used for eliminating the defect that the existing carbon fiber fully-wound hydrogen storage gas cylinder (IV-type gas cylinder) mouth structure with a plastic liner for high pressure easily causes hydrogen leakage due to fatigue failure under the use working condition, has reliable sealing structure and simple and convenient assembly, and can keep stable sealing in the carbon fiber winding manufacturing process of the gas cylinder and the cylinder valve assembling and disassembling process when the gas cylinder is used.

In order to achieve the above purpose, the solution adopted by the invention is as follows:

a sealing structure suitable for a high-pressure gas cylinder comprises an annular coaxial inner cylinder body and an annular outer cylinder body, wherein the outer cylinder body is provided with an annular base which is matched with a shoulder part of an inner container to be sealed; a middle annular hollow structure is arranged between the inner cylinder body and the outer cylinder body and is used for embedding a bottle mouth of the inner container to be sealed; the inner cylinder body is provided with a sealing groove at one side contacting with the bottle mouth of the inner container to be sealed, and a sealing piece is arranged in the sealing groove to prevent gas from leaking from a gap between the inner cylinder body and the bottle mouth of the inner container to be sealed.

Furthermore, the inner side of the base of the outer cylinder body is provided with a plurality of grooves matched with the convex rafters on the outer surface of the inner container to be sealed, and the grooves are symmetrically and uniformly distributed along the circular base.

Optionally, the groove is shaped like a cuboid; and/or the number of the grooves is 4-8; and/or the number of the grooves is 6, and on the same plane, the included angles between the centers of two adjacent grooves and the line connecting the centers of the two adjacent grooves are both 60 degrees.

Optionally, the inner cylinder and the outer cylinder are of an integrated structure; and/or, the seal groove comprises an upper coaxial annular seal groove and a lower coaxial annular seal groove: a first sealing groove and a second sealing groove; and/or the sealing element is an O-shaped ring and a retainer ring.

Optionally, the interval between the first sealing groove and the second sealing groove 15 is not more than 2cm, preferably 1 cm; and/or the distance between the second sealing groove and the opening of the inner container to be sealed is not more than 2cm, preferably 1 cm.

Optionally, the inner cylinder body comprises an upper wide-caliber structure and a lower narrow-caliber structure, and the caliber size of the inner cylinder body is matched with that of the cylinder valve for the gas cylinder; and/or the wide-caliber structure is internally provided with internal threads which are matched with the external threads of the cylinder valve for the gas cylinder and used for fixing the cylinder valve; and/or the narrow-diameter part is a smooth surface which is matched with an original sealing ring on a bottle valve for the gas storage bottle, and gas is prevented from leaking from a gap between the bottle opening and the bottle valve; and/or the sealing structure is made of aluminum alloy or stainless steel.

Optionally, a sealing groove is formed in a contact surface of the top of the bottle mouth of the inner container to be sealed and the bottom of the annular hollow structure between the inner cylinder and the outer cylinder, and an O-ring is placed in the sealing groove to enhance sealing.

Optionally, a plurality of protruding rafters matched with the grooves on the inner side of the base of the outer cylinder body are arranged on the outer side of the bottom of the bottle mouth of the inner container to be sealed, and the protruding rafters are symmetrically and uniformly distributed along the bottle mouth.

Optionally, the convex rafters are shaped like cuboids; and/or the number of the convex rafters is 4-8; and/or the number of the convex rafters is 6, and on the same plane, the included angles between the centers of two adjacent grooves and the connecting line of the circle centers are both 60 degrees.

Optionally, a cylinder is pre-embedded in the bottle mouth of the liner to be sealed so as to reduce strain of the bottle mouth under a high-pressure working condition, and the cylinder and the bottle mouth of the liner to be sealed are on the same axis.

Optionally, a plurality of round holes are formed in the middle or the lower part of the cylinder body of the cylinder to increase the bonding strength between the cylinder and the liner bottle mouth.

Optionally, the circular holes are symmetrically and uniformly distributed along the circumferential direction, and the centers of all the circular holes are on the same plane; and/or the diameter of the round hole is not more than 1cm, and the preferred diameter is 0.6 cm; and/or 12 round holes are arranged on the same cross section, and the included angle between the center of each two adjacent round holes and the connecting line of the circle centers is 30 degrees; and/or the cylinder is a stainless steel cylinder with the thickness of 1mm and the height of 3 cm; and/or the cylinder is a stainless steel cylinder.

Optionally, the bottle mouth of the liner required to be sealed and the liner cylinder body are integrally formed; and/or the bottle mouth of the liner and the cylinder body of the liner to be sealed are molded by blow molding or injection molding.

Optionally, the shoulder of the outer cylinder and the outer layer of the inner container to be sealed are wound with carbon fibers to form a carbon fiber resin composite layer.

The sealing structure suitable for the high-pressure gas cylinder is applied to the vehicle-mounted high-pressure hydrogen storage cylinder.

Further, the bottle mouth structure of the high-pressure IV-type hydrogen storage bottle with a reliable and stable sealing structure comprises a metal bottle mouth, a plastic liner and a carbon fiber composite layer. The bottle mouth of the hydrogen storage bottle is circular and communicated, the metal bottle mouth and the plastic liner bottle mouth are on the same axis, the plastic liner bottle mouth is embedded into the metal bottle mouth, and carbon fibers are wound on the shoulder of the metal bottle mouth and the outer layer of the plastic liner to form a carbon fiber resin composite layer.

The metal bottle mouth material is one of aluminum alloy or stainless steel, the bottle mouth is divided into a wide-caliber structure at the upper part and a narrow-caliber structure at the lower part, and the caliber size is matched with the size of the metal bottle valve for the hydrogen storage bottle. The internal thread is arranged in the upper wide-caliber structure and matched with the external thread of the cylinder valve, and the internal thread is used for fixing the cylinder valve. The narrow-mouth part at the lower part is a metal smooth surface, and the original sealing ring on the cylinder valve is utilized to prevent hydrogen from leaking from a gap between the gas cylinder mouth and the cylinder valve, so that the stable sealing of the metal cylinder mouth and the metal cylinder valve under the repeated high-low pressure charging and discharging working conditions is realized.

The metal bottle mouth is of a coaxial annular cylinder body integrated structure, the outer cylinder body is a carbon fiber winding support piece, the inner cylinder body is a sealing surface support body, the annular hollow structure between the two cylinder bodies is used for being embedded into a plastic inner container bottle mouth, and the cap wearing structure enables the assembly between the metal bottle mouth and the plastic inner container to be simple and convenient.

The contact side of the cylinder body in the metal bottle mouth and the plastic liner is provided with two sealing grooves, and each sealing groove is internally provided with a set of O-shaped ring and a check ring for preventing hydrogen from leaking from a gap between the metal bottle mouth and the plastic liner.

The outer cylinder body of the metal bottle opening is provided with a base which is matched with the shoulder of the plastic liner, and the carbon fiber composite material is wound on the outer side of the base to reinforce the shoulder strength of the gas cylinder with the plastic liner. The inner side of the outer barrel base is provided with grooves similar to a cuboid, the grooves are symmetrically and uniformly distributed along the circular base, and the number of the grooves is 4-8.

The plastic inner container is formed by integrating a plastic inner container body and a plastic inner container bottle mouth. The plastic liner bottle neck bottom outside has the protruding rafter of class cuboid shape, and protruding rafter is along bottle neck symmetry evenly distributed, and protruding rafter quantity is 4 ~ 8.

The plastic inner container bottle mouth has the advantages that the convex rafter on the outer side of the bottom of the plastic inner container bottle mouth is embedded into the groove on the inner side of the outer cylinder body base of the metal bottle mouth, the concave rafter and the groove are matched for use, the flange structure design has the advantages that the metal bottle mouth is prevented from peeling off the plastic inner container during the carbon fiber winding process in the IV-type hydrogen storage bottle manufacturing process, the carbon fiber winding cannot be carried out, the metal bottle mouth is prevented from peeling off the plastic inner container to rotate due to the opposite torque acting force of the bottle valve in the installation and disassembly process of the IV-type.

The metal cylinder is embedded in the plastic liner bottle neck, the metal cylinder and the plastic liner bottle neck are on the same axis, and the metal cylinder is arranged, so that the strain of the plastic liner bottle neck under a high-pressure working condition is reduced, the structural stability of the plastic liner bottle neck is improved, and the sealing reliability between the metal bottle neck and the plastic liner is further improved.

The metal cylinder material chooses one of aluminum alloy or stainless steel for use, and the stack shell of metal cylinder has the diameter to be not more than 1 cm's cavity round hole, and the round hole is along the circumferencial direction symmetry evenly distributed, and the round hole quantity is 4 ~ 20. The metal cylinder is provided with the holes, so that the bonding strength of the metal cylinder and the plastic liner is improved.

The contact surface between the top of the plastic liner bottle mouth and the bottom of the annular hollow structure of the metal bottle mouth is provided with a sealing groove, and an O-shaped ring is placed in the sealing groove to enhance the sealing reliability between the metal bottle mouth and the plastic liner.

Due to the adoption of the scheme, the invention has the following characteristics:

1. the unique coaxial annular cylinder body integrated cap-wearing structure of the metal bottle opening and the rafter structure between the metal bottle opening and the plastic liner enable the gas cylinder to be simple to manufacture and assemble and to be more stable in structure in the using process.

2. The metal bottle mouth is of a coaxial annular cylinder body integrated structure, and the reliability and the stability of hydrogen sealing of the bottle mouth of the high-pressure IV-type hydrogen storage bottle are greatly improved by combining the systematic design of pre-embedding of a metal cylinder of a plastic liner bottle mouth and an O-shaped ring sealing groove.

Drawings

FIG. 1 is a schematic view showing the overall structure of a carbon fiber fully-wrapped hydrogen storage cylinder mouth suitable for a high-pressure plastic liner according to a preferred embodiment of the invention.

Fig. 2 is a schematic view of the metal bottle mouth structure in the embodiment shown in fig. 1.

Figure 3 is a top view of the plastic liner spout of the embodiment of figure 1.

Fig. 4 is a view showing the configuration of the metal cylinder in the embodiment shown in fig. 1.

Detailed Description

The invention will be further described with reference to the following examples, which are illustrated in the accompanying drawings.

The invention relates to a bottle mouth structure of a high-pressure IV-type hydrogen storage bottle with a reliable and stable sealing structure, which mainly comprises a metal bottle mouth, a plastic liner and a carbon fiber composite layer. One example of the invention is a bottle mouth structure of a hydrogen storage bottle with a plastic liner and carbon fiber fully wound, wherein the nominal working pressure is 70MPa, and the water volume is 60L.

FIG. 1 is a schematic structural view of a high-pressure plastic liner carbon fiber fully-wrapped hydrogen storage cylinder according to an embodiment of the present invention. The IV-type hydrogen storage bottle comprises a metal bottle mouth 1, a plastic inner container 2 and a carbon fiber composite material layer 3. The bottle mouth structure of the hydrogen storage bottle is circular and through, the metal bottle mouth 1 and the plastic liner bottle mouth 21 are on the same axis, the plastic liner bottle mouth 21 is embedded into the metal bottle mouth 1, and carbon fibers are wound on the shoulder of the metal bottle mouth 1 and the outer layer of the plastic liner 2 to form a carbon fiber composite material layer 3.

FIG. 2 is a schematic view showing the structure of a metal bottle mouth 1 according to an embodiment of the present invention, which is a 6061 aluminum alloy metal bottle mouth, the mouth is divided into an upper wide-caliber structure and a lower narrow-caliber structure, and the caliber size is matched with the size of a metal bottle valve for a hydrogen storage bottle. An internal thread 11 is arranged in the upper wide-caliber structure, and the internal thread 11 is matched with an external thread of the cylinder valve and used for fixing the cylinder valve. The narrow-mouth part at the lower part is a metal smooth surface, and the original sealing ring on the cylinder valve is utilized to prevent hydrogen from leaking from a gap between the gas cylinder mouth and the cylinder valve, so that the stable sealing of the metal cylinder mouth and the metal cylinder valve under the repeated high-low pressure charging and discharging working conditions is realized.

The metal bottle mouth 1 is a coaxial annular cylinder integrated structure, the outer cylinder 12 is a carbon fiber winding support piece, the inner cylinder 13 is a sealing surface support body, the annular hollow structure between the two cylinders is used for being embedded into the plastic liner bottle mouth 21, and the cap wearing structure enables the assembly between the metal bottle mouth 1 and the plastic liner 2 to be simple and convenient. The contact side of the metal bottle mouth inner cylinder body 13 and the plastic liner 21 is provided with an upper coaxial annular sealing groove and a lower coaxial annular sealing groove: each of the first sealing groove 14 and the second sealing groove 15 is provided with a set of rubber O-shaped ring 16 and a Teflon check ring 17 for blocking hydrogen from leaking from a gap between the metal bottle mouth inner cylinder body 13 and the plastic inner container 21. The interval between the first sealing groove 14 and the second sealing groove 15 is not more than 2cm, preferably 1cm, and the distance between the second sealing groove 15 and the mouth of the plastic liner is not more than 2cm, preferably 1 cm.

The outer cylinder body 12 of the metal bottle mouth is provided with a base which is matched with the shoulder of the plastic liner 2, and the carbon fiber composite material layer 3 is wound outside the base to strengthen the shoulder strength of the gas cylinder with the plastic liner. The inner side of the base of the outer cylinder body 12 is provided with grooves 18 similar to cuboid shapes, the grooves 18 are symmetrically and uniformly distributed along the circular base, and the number of the grooves is 6; on the same plane, the included angle between the center of each adjacent groove and the connecting line of the circle centers is 60 degrees.

Referring to fig. 1, the plastic liner 2 is formed by integrating a plastic liner bottle mouth 21 and a liner cylinder body 22. The plastic inner container is formed by blowing or injection molding of nylon 6. The outer side of the bottom of the bottle mouth 21 of the plastic liner is provided with a plurality of convex rafters 23 which are matched with the grooves 18 for use and are in the shape of a similar cuboid, the convex rafters 23 are symmetrically and uniformly distributed along the bottle mouth, and the number of the convex rafters is 6; on the same plane, the included angle between the center of each of the two adjacent flanges and the connecting line of the circle centers is 60 degrees, as shown in fig. 3. A sealing groove 24 is formed in the contact surface of the top of the plastic liner bottle mouth 21 and the bottom of the annular hollow structure of the metal bottle mouth 2, and a rubber O-shaped ring 25 is placed in the sealing groove 24, so that the sealing reliability between the metal bottle mouth and the plastic liner is enhanced. The convex rafter 23 at the outer side of the bottom of the plastic liner bottle mouth 21 is embedded into the groove 18 at the inner side of the base of the outer cylinder body 12 of the metal bottle mouth. The flange structure design has the advantages of preventing the carbon fiber winding from being disabled due to the fact that the plastic liner is peeled off from the metal bottle opening during the carbon fiber winding period in the manufacturing process of the IV-type hydrogen storage bottle, preventing the plastic liner from being peeled off from the metal bottle opening due to the fact that a bottle valve is installed and detached in the application process of the IV-type hydrogen storage bottle, and keeping the structural stability of the IV-type hydrogen storage bottle. The metal cylinder 26 is embedded in the plastic liner bottle mouth 21, the metal cylinder 26 and the plastic liner bottle mouth 21 are on the same axis, and the metal cylinder is arranged, so that the strain of the plastic liner bottle mouth 21 under a high-pressure working condition is reduced, the structural stability of the plastic liner bottle mouth 21 is improved, and the sealing reliability between the metal bottle mouth 1 and the plastic liner 2 is further improved.

FIG. 4 is a view showing an outline configuration of a metal cylinder 26 according to an embodiment of the present invention, which is a stainless steel cylinder having a thickness of 1mm and a cylinder height of 3cm, and which may be provided with hollow circular holes 27 having a diameter of not more than 1cm, preferably circular holes 27 having a diameter of 0.6cm, at the middle and lower portions of the cylinder body; the circular holes 27 are symmetrically and uniformly distributed along the circumferential direction, the centers of all the circular holes are required to be on one plane, and the number of the circular holes 27 is 12; on the same cross section, the included angle between the center of each two adjacent circular holes 27 and the connecting line of the circle centers is 30 degrees. The advantage of the metal cylinder with through holes is that the bonding strength between the metal cylinder 26 and the plastic liner bottle mouth 21 is increased.

The embodiments described above are intended to facilitate the understanding and appreciation of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the embodiments described herein, and those skilled in the art can make modifications and alterations without departing from the scope of the present invention.

Claims

1. The utility model provides a seal structure suitable for high-pressure plastic inner bag carbon fiber twines gas cylinder entirely which characterized in that: the inner container sealing device comprises an annular coaxial inner cylinder and an annular outer cylinder, wherein the outer cylinder is provided with an annular base which is matched with a shoulder part of an inner container to be sealed; a middle annular hollow structure is arranged between the inner cylinder body and the outer cylinder body and is used for embedding a bottle mouth of the inner container to be sealed; the inner cylinder body is provided with a sealing groove at one side contacting with the bottle mouth of the inner container to be sealed, and a sealing piece is arranged in the sealing groove to prevent gas from leaking from a gap between the inner cylinder body and the bottle mouth of the inner container to be sealed.

2. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the inner side of the base of the outer cylinder body is provided with a plurality of grooves matched with the convex rafters on the outer surface of the inner container to be sealed, and the grooves are symmetrically and uniformly distributed along the circular base.

3. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 2, wherein: the groove is in a shape similar to a cuboid; and/or the number of the grooves is 4-8; and/or the number of the grooves is 6, and on the same plane, the included angles between the centers of two adjacent grooves and the line connecting the centers of the two adjacent grooves are both 60 degrees.

4. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the inner cylinder body and the outer cylinder body are of an integrated structure; and/or, the seal groove comprises an upper coaxial annular seal groove and a lower coaxial annular seal groove: a first sealing groove and a second sealing groove; and/or the sealing element is an O-shaped ring and a retainer ring.

5. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 4, wherein: the interval between the first sealing groove and the second sealing groove 15 is not more than 2cm, and preferably 1 cm; and/or the distance between the second sealing groove and the opening of the inner container to be sealed is not more than 2cm, preferably 1 cm.

6. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the inner cylinder body comprises a bottle opening, a valve body and a valve seat, wherein the bottle opening comprises an upper wide-caliber structure and a lower narrow-caliber structure, and the caliber size of the inner cylinder body is matched with that of the bottle valve for the gas storage bottle; and/or the wide-caliber structure is internally provided with internal threads which are matched with the external threads of the cylinder valve for the gas cylinder and used for fixing the cylinder valve; and/or the narrow-diameter part is a smooth surface which is matched with an original sealing ring on a bottle valve for the gas storage bottle, and gas is prevented from leaking from a gap between the bottle opening and the bottle valve; and/or the sealing structure is made of aluminum alloy or stainless steel.

7. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the bottle neck top of the inner container to be sealed and the bottom contact surface of the annular hollow structure between the inner barrel and the outer barrel are provided with sealing grooves, and O-shaped rings are placed in the sealing grooves to strengthen sealing.

8. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the outer side of the bottom of the bottle mouth of the inner container to be sealed is provided with a plurality of convex rafters matched with the grooves on the inner side of the base of the outer barrel body, and the convex rafters are symmetrically and uniformly distributed along the bottle mouth.

9. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 8, wherein: the convex rafters are of a cuboid-like shape; and/or the number of the convex rafters is 4-8; and/or the number of the convex rafters is 6, and on the same plane, the included angles between the centers of two adjacent grooves and the connecting line of the circle centers are both 60 degrees.

10. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the cylinder is embedded in the bottle mouth of the inner container to be sealed so as to reduce the strain of the bottle mouth under the high-pressure working condition, and the cylinder and the bottle mouth of the inner container to be sealed are on the same axis.

11. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 10, wherein: the middle part or the lower part of the cylinder body of the cylinder is provided with a plurality of round holes so as to increase the bonding strength of the cylinder and the liner bottle mouth.

12. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 11, wherein: the circular holes are symmetrically and uniformly distributed along the circumferential direction, and the centers of all the circular holes are on the same plane; and/or the diameter of the round hole is not more than 1cm, and the preferred diameter is 0.6 cm; and/or 12 round holes are arranged on the same cross section, and the included angle between the center of each two adjacent round holes and the connecting line of the circle centers is 30 degrees; and/or the cylinder is a stainless steel cylinder with the thickness of 1mm and the height of 3 cm; and/or the cylinder is a stainless steel cylinder.

13. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: the bottle mouth of the inner container to be sealed and the cylinder body of the inner container are integrally formed; and/or the bottle mouth of the liner and the cylinder body of the liner to be sealed are molded by blow molding or injection molding.

14. The sealing structure suitable for the high-pressure plastic liner carbon fiber fully-wound gas cylinder as claimed in claim 1, wherein: and the shoulder of the outer cylinder body and the outer layer of the inner container to be sealed are wound with carbon fibers to form a carbon fiber resin composite layer.

15. The use of the sealing structure suitable for a carbon fiber fully-wrapped gas cylinder with a high-pressure plastic liner according to any one of claims 1 to 14 in an on-vehicle high-pressure hydrogen storage cylinder.